Swearing that the inheritance is unlawful for him

Q: In 1390 A.H., my father bought a piece of agricultural land in the north of (...). (Part No. 23; Page No. 185) As he was an old man and he had no certified documents, the municipality filed a case against him, denying his ownership of this land. Being his eldest son, I became the lawyer of my father, and the municipality appointed another lawyer for them. Praise be to Allah, the truth is always victorious. After submitting the official documents to my father, which took place ten years ago, I moved to Riyadh because my wife fell ill, where she underwent a surgical operation, and she frequented Sahara Hospital. Five years later, one of my children fell ill, so I took him to (...) so that a shaykh would recite Qur'an over him. During that visit, I stayed with my brother (...), who is an army officer, at our father's. This was during the summer holidays.I had a quarrel with my brother, as my brothers forgot what I had done for them. Being worried about my ill son, and being at that age, I got angry at his words. Being the eldest son and having born a great responsibility, I swore by Allah, the Greatest, that this inheritance is unlawful for me. My mother and one of my brothers were present at that time. My mother was touched by my oath, so I said I will ask His Eminence, Shaykh Ibn Baz. (Part No. 23; Page No. 186) Please advise concerning what I should do and what should be based on my oath. May Allah protect you.

A: It is impermissible for a person to render lawful things unlawful for themselves, such as food, drinks, clothes, or lawful money. If a person does so, they have to pay the Kaffarah (expiation) of an oath, according to Allah's saying, O Prophet! Why do you forbid (for yourself) that which Allâh has allowed to you until His saying, Allâh has already ordained for you (O men) the absolution from your oaths. Thus, you have to take your share of your father's inheritance, being a lawful right for you that you cannot prohibit on yourself. You have to also pay the Kaffarah of an oath, which is feeding ten needy people, a kilogram and a half each of wheat, rice or so, clothing them or emancipating a believing slave. If you cannot do either, you have to observe Sawm (fasting) for three days to expiate for your oath.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.